Pan-retroviral nucleocapsid-mediated phase separationregulates genomic RNA positioning and trafficking

Membraneless organelles are formed by liquid-liquid phase separation of disordered protein prion-like domains (PrLDs), RNA-binding motifs (RRMs) & Zinc fingers (ZnFs)

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Like HIV-1 Nucleocapsid (NC), cellular RNA-binding, helicases and chaperones, such as G3BP1, TIAR, TIA-1, DDX6, TDP-43, FUS/TLS, Tau, and hnRNP proteins, are also components of stress granules (SGs) and P-bodies (PBs), can be Zn2+-regulated, and form liquid-liquid phase separation (LLPS) condensates due to their low-complexity, intrinsically disordered prion-like domains (PrLDs).

Pan-retrovirus Gag proteins have conserved PrLDs, ZnFs, and RRMs, and undergo Nucleocapsid-mediated ZnF and Zn2+-dependent liquid-liquid phase separation (LLPS)

Abbrev: PrLD, prion-like domain;

RRM, RNA-binding motif;

ZnF, zinc finger

Abbrev:

TPEN, Zn2+ chelator;

ADA & DIBA-1, HIV-1 specific Zn2+ ejectors;

freeze/thaw, mechanical Zn2+ depletion

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Monette A. et al. Cell Rep. 2020 Apr 21.

Abbrev: Zn2+, zinc; ZnF, zinc finger; SG, stress granule;

vRNA, viral genomic RNA; ARS, arsenite;

LLPS, liquid-liquid phase separation

X X

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Monette A. et al. Cell Rep. 2020 Apr 21.

NC ZnF mutants cause SG-vRNA accumulation & reverse HIV-1 blockade on SGs & NC-LLPS formed in live cells are ZnF-dependent and Zn2+-chelation sensitive

Acknowledgements

During the COVID-19 pandemic, virus transmission is now often

described in terms of “aerosols” or “droplets”. Bioinformatics, in

vitro, and cellular immunofluorescence and biochemical

approaches are used to explore pan-retrovirus assembly in terms

of liquid-liquid phase separation. Photography by Anne Monette.

Andrew MoulandMeijuan NiuLois ChenShringar RaoSergio AlpuchePaola GuizarGabriel Guajardo ContrerasAna Luiza Abdalla

Robert GorelickDonald JohnsonCathy Hixson

Imed GallouziMaureen OlivieraIlinca IbanescuCesar CollazosBonnie SpiraColin CristSolene JametHenry YuStephane RichardRongtuan LinChia-Hao ChangChristian YoungLDI cell imaging facility